XV. c
"It's better to light a candle than to curse the darkness" — Carl Sagan We all love things that are constant, predictable, with no surprises and as a consequence the world of Science is full of it... constants. Here's a few for illustration purposes: Speed of light in vacuum Gravitational constant Planck constant Electric constant / Vacuum Permittivity Magnetic constant / Vacuum Permeability Cosmological constant There are loads of them used for the most varied purposes, from rocket launches to utilities meter readings. We tend to forget how they came about, the process that lead to the calculated figures above. It all started with measuring, collecting data from experiments, finding that there is a relationship between the measurements and the common factor between them all. A constant is just a common factor between physical entities. Through time, measurements got more accurate, experiments more precise, predictions on new outcomes more
